Fabrication and Application of Polyethylenimine/Ca-Alginate Blended Hydrogel Fibers as High-Capacity Adsorbents for Recovery of Gold from Acidic Solutions

2017 ◽  
Vol 262 ◽  
pp. 103-106 ◽  
Author(s):  
John Kwame Bediako ◽  
Myung Hee Song ◽  
Yeoung Sang Yun
Keyword(s):  
High Capacity ◽  
Metallic Gold ◽  
X Ray Diffraction ◽  
Acidic Solutions ◽  
Xrd Study ◽  
Desorption Study ◽  
Alginate Fibers ◽  
Direct Adsorption ◽  
Ca Alginate ◽  
Alginate Matrix

High-capacity polyethylenimine (PEI)/Ca-alginate blended hydrogel fibers were fabricated via three steps, viz. electrostatic blending of PEI and alginate, ionotropic gelation of alginate and CaCl2, and fixing of PEI into the Ca-alginate matrix, using glutaraldehyde (GA) as a crosslinker. Two crosslinking approaches resulted in different stabilities and gold uptake capacities of the prepared sorbents. Post-crosslinking approach was more efficient than pre-crosslinking likely owing to the better crosslinking efficiency, leading to better stability and sorption capacity. Furthermore, X-ray diffraction (XRD) study revealed the reduction of Au (III) to metallic gold, Au (0) in the crosslinked fibers. The Au (0) predominancy was confirmed with a metal desorption study. The present study thus demonstrates the possibility of recovering metallic gold from aqueous solutions by direct adsorption-coupled-reduction approach using GA-crosslinked PEI/Ca-alginate fibers.

Ball-Milled Graphite-Tin Composite Anode Materials for Lithium-Ion Battery

2012 ◽  
Vol 736 ◽  
pp. 127-132
Author(s):  
Kuldeep Rana ◽  
Anjan Sil ◽  
Subrata Ray
Keyword(s):  
Lithium Ion Battery ◽  
Anode Materials ◽  
High Capacity ◽  
Lithium Ion ◽  
Composite Anode ◽  
X Ray Diffraction ◽  
Promising Alternative ◽  
X Ray ◽  
Initial Discharge ◽  
Lithium Ion Cell

Lithium alloying compounds as an anode materials have been a focused for high capacity lithium ion battery due to their highenergy capacity and safety characteristics. Here we report on the preparation of graphite-tin composite by using ball-milling in liquid media. The composite material has been characterized by scanning electron microscope, energy depressive X-ray spectroscopy, X-ray diffraction and Raman spectra. The lithium-ion cell made from graphite-tin composite presented initial discharge capacity of 1065 mAh/g and charge capacity 538 mAh/g, which becomes 528 mAh/g in the second cycle. The composite of graphite-tin with higher capacity compared to pristine graphite is a promising alternative anode material for lithium-ion battery.

Novel-shaped LiNi1/3Co1/3Mn1/3O2 prepared by a hydroxide coprecipitation method

2008 ◽  
Vol 80 (11) ◽  
pp. 2537-2542 ◽  
Author(s):  
Zexun Tang ◽  
Deshu Gao ◽  
Ping Chen ◽  
Zhaohui Li ◽  
Qiang Wu
Keyword(s):  
Specific Capacity ◽  
High Capacity ◽  
Coprecipitation Method ◽  
X Ray Diffraction ◽  
Capacity Retention ◽  
Uniform Size ◽  
Li Ion ◽  
New Generation ◽  
Optimized Conditions ◽  
Hydroxide Coprecipitation

Ni1/3Co1/3Mn1/3(OH)2, a precursor of LiNi1/3Co1/3Mn1/3O2 in new-generation Li-ion batteries, was prepared by a hydroxide coprecipitation method. Scanning electronic microscopy (SEM) micrographs reveal that the precursor particles thus obtained, show regular shape with uniform size under optimized conditions. X-ray diffraction (XRD) indicates that well-ordered layer-structured LiNi1/3Co1/3Mn1/3O2 was prepared after calcination at high temperature. The final product exhibited a spherical morphology with uniform size distribution (10 μm in diameter). At the terminal charging voltage of 4.3 and 4.5 V (vs. Li/Li+), the testing cells of LiNi1/3Co1/3Mn1/3O2 delivered a specific capacity of 161.2 and 184.1 mAh g-1, respectively. The high capacity retention of 98.0 and 96.1 % after charging to 4.3 and 4.5 V for 50 cycles, respectively, indicates that this material displays excellent cycling stability even at high cut-off voltage.

Preparation and characterization of poly (ethylene glycol) grafted Ca-alginate fibers by γ-irradiation for biomedical applications

2013 ◽  
Vol 27 (2) ◽  
pp. 216-226 ◽  
Author(s):  
Md. Kamal Khan ◽  
Mohammed Mizanur Rahman ◽  
Bodrun Nesa ◽  
Romana Nasrin ◽  
Swajal Molla ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Biomedical Applications ◽  
Poly Ethylene Glycol ◽  
Γ Irradiation ◽  
Alginate Fibers ◽  
Poly Ethylene ◽  
Ca Alginate

Structural-phase transition in (Cu2Te)2−x(ZnTe)x at high temperature

2021 ◽  
pp. 2150113
Author(s):  
H. B. Gasimov ◽  
R. M. Rzayev
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
High Temperature ◽  
Single Crystals ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Xrd Study ◽  
Xrd Method

Cu2Te single crystal was grown by the Bridgman method. X-ray diffraction (XRD) study of Cu2Te single crystals in the temperature range of 293–893 K was performed and possible phase transitions in the mentioned range of temperature have been investigated. (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals also were grown with [Formula: see text], 0.05, 0.10 concentrations and structural properties of the obtained single crystals were investigated by the XRD method in the temperature range 293–893 K. Lattice parameters and possible phase transitions in the mention temperature range were determined for (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals for [Formula: see text], 0.05, 0.10 concentrations.

Evolution structurale de la nacrite en fonction de la nature des molécules organiques intercalees

2000 ◽  
Vol 33 (6) ◽  
pp. 1351-1359 ◽  
Author(s):  
A. Ben Haj Amara ◽  
H. Ben Rhaiem ◽  
A. Plançon
Keyword(s):  
Ir Spectroscopy ◽  
Hydrogen Bonds ◽  
Dimethyl Sulfoxide ◽  
Organic Molecules ◽  
Interlayer Space ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intercalated Compounds ◽  
Xrd Study ◽  
Intercalation Process

Nacrite has been intercalated with two polar organic molecules: dimethyl sulfoxide (DMSO) andN-methylacetamide (NMA). The homogeneous nacrite complexes have been studied by X-ray diffraction (XRD) and infrared (IR) spectroscopy. The XRD study is based on a comparison between experimental and calculated patterns. The structures of the intercalated compounds have been determined, including the mutual positions of the layers after intercalation and the positions of the intercalated molecules in the interlayer space. It has been shown that the intercalation process causes not only a swelling of the interlayer space but also a shift in the mutual in-plane positions of the layers. This shift depends on the nature of the intercalated molecules and is related to their shape and the hydrogen bonds which are established with the surrounding surfaces. For a given molecule, the intercalation process is the same for the different polytypes of the kaolinite family. These XRD results are consistent with those of IR spectroscopy.

scholarly journals Preparation of Powders Containing Sb, Ni, and O for the Design of a Novel CO and C3H8 Sensor

2021 ◽  
Vol 11 (20) ◽  
pp. 9536
Author(s):  
Jorge Alberto Ramírez-Ortega ◽  
José Trinidad Guillén-Bonilla ◽  
Alex Guillén-Bonilla ◽  
Verónica María Rodríguez-Betancourtt ◽  
Lorenzo Gildo-Ortiz ◽  
...  
Keyword(s):  
Response Times ◽  
High Capacity ◽  
Dynamic Tests ◽  
X Ray Diffraction ◽  
Wet Chemistry ◽  
Good Thermal Stability ◽  
Great Performance ◽  
Vis Spectroscopy ◽  
Recovery Times ◽  
Response And Recovery

In this work, powders of NiSb2O6 were synthesized using a simple and economical microwave-assisted wet chemistry method, and calcined at 700, 800, and 900 °C. It was identified through X-ray diffraction that the oxide is a nanomaterial with a trirutile-type structure and space group P42/mnm (136). UV–Vis spectroscopy measurements showed that the bandgap values were at ~3.10, ~3.14, and ~3.23 eV at 700, 800, and 900 °C, respectively. Using scanning electron microscopy (SEM), irregularly shaped polyhedral microstructures with a size of ~154.78 nm were observed on the entire material’s surface. The particle size was estimated to average ~92.30 nm at the calcination temperature of 900 °C. Sensing tests in static atmospheres containing 300 ppm of CO at 300 °C showed a maximum sensitivity of ~72.67. On the other hand, in dynamic atmospheres at different CO flows and at an operating temperature of 200 °C, changes with time in electrical resistance were recorded, showing a high response, stability, and repeatability, and good sensor efficiency during several operation cycles. The response times were ~2.77 and ~2.10 min to 150 and 200 cm3/min of CO, respectively. Dynamic tests in propane (C3H8) atmospheres revealed that the material improved its response in alternating current signals at two different frequencies (0.1 and 1 kHz). It was also observed that at 360 °C, the ability to detect propane flows increased considerably. As in the case of CO, NiSb2O6’s response in propane atmospheres showed very good thermal stability, efficiency, a high capacity to detect C3H8, and short response and recovery times at both frequencies. Considering the great performance in propane flows, a sensor prototype was developed that modulates the electrical signals at 360 °C, verifying the excellent functionality of NiSb2O6.

scholarly journals X-RAY DIFFRACTION ANALYSIS OF MRITYUNJAYA RASA

2021 ◽  
Vol 9 (8) ◽  
pp. 1637-1641
Author(s):  
Abhishek Abhishek
Keyword(s):  
Diffraction Analysis ◽  
X Ray Diffraction ◽  
Minor Phase ◽  
Major Phase ◽  
X Ray ◽  
Xrd Study

Introduction: Mrityunjaya Rasa is a Herbo-Mineral formulation, mentioned in Jwara Chikitsa along with various Anupana like Madhu, Aardraka Swarasa, and Jeeraka Kashaya with Guda. Ingredients like Shudha Hingula, Shudha Gandhaka, Shudha Vatsanabha, Shudha Tankana, Pippali and Maricha with properties of Tikta, Katu Rasa Teekshna Guna and Deepana-Pachana, Swedajanana, Yogavahi and Jwaraghna action show the significant result on various types of fever. To attain desired qualities in the finished product, it is much needed to check efficacy on modern parameters for standardization purposes. Thus, Mrityunjaya Rasa was subjected to X- ray diffraction spectroscopy to ensure SOPs followed for preparation. Aim: The study aimed to analyse the results of X-ray diffraction spectroscopy of Mrityunjaya Rasa. Materials and Methods: X-ray diffraction spectroscopy of Mrityunjaya Rasa was carried out at MIT–central instrumentation facility – innovation centre, Manipal, Udupi. Results: XRD study indicates that Mrityunjaya Rasa contains HgS (cinnabar), mercury sulphide in major phase and borax and elements Na, Ca, Mn, Mg, K, P, Zn, C, Cl2, Fe and B in minor phase. Conclusions: Mrityunjaya Rasa contains HgS (cinnabar), mercury sulphide in major phase and borax and other elements like Na, Ca, Mn, Mg, K, P, Zn, C, Cl2, Fe, and B are also present. Compounds and elements are present due to ingredients and Shodhana media which were used. This study can be a path for establishing the thumbprint of SOP for Mrityunjaya Rasa, a herbomineral compound formulation. Keywords: Mrityunjaya Rasa, XRD, HgS, S, Borax, Na, Ca, Mn etc.

scholarly journals Formation of metal oxide-based hydroxysodalite by alkali-activation of kaolinite

Chemija ◽  
2020 ◽  
Vol 31 (3) ◽  
Author(s):  
Ehab AlShamaileh ◽  
Muayad Esaifan ◽  
Qusay Abu-Afifeh
Keyword(s):  
Activation Energy ◽  
Metal Oxide ◽  
Alkali Activation ◽  
Dsc Analysis ◽  
X Ray Diffraction ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Xrd Study ◽  
Dsc Curves

The formation of metal oxide-based hydroxysodalite by alkali-activation of kaolinite is studied using X-ray diffraction (XRD) study and differential scanning calorimetry (DSC) analysis. Different metal oxides (CoO, MgO, FeO and SiO2) were used to form the metal oxide-based hydroxysodalite. The transformation from kaolinite into hydroxysodalite is confirmed by XRD. In the thermodynamic study, the maximum peak temperatures for DSC curves at various heating rates were used to determine the activation energy (Ea) of the hydroxysodalite formation. With magnesium oxide and cobalt oxide, the formation process was found to be exothermic while it was endothermic with iron oxide.

scholarly journals Solid-state reaction in nanoparticulate alumina/LZSA glass-ceramic composites

Cerâmica ◽  
2018 ◽  
Vol 64 (371) ◽  
pp. 397-402
Author(s):  
O. R. K. Montedo ◽  
F. Raupp-Pereira ◽  
A. P. N. de Oliveira
Keyword(s):  
Solid State ◽  
Glass Ceramic ◽  
Coefficient Of Thermal Expansion ◽  
Raw Materials ◽  
Glass Frit ◽  
Ceramic Composites ◽  
Solid State Reactions ◽  
X Ray Diffraction ◽  
Dry Powders ◽  
Xrd Study

Abstract In this work, some properties, such as sinterability, modulus of elasticity (E), coefficient of thermal expansion (CTE) and dielectric constant (εr), of composites constituted by nanoparticulate alumina (27-43 nm, 35 m2.g-1) in different contents (0 to 77 vol%) and a LZSA glass-ceramic composition (17.7Li2O-5.2ZrO2-68.1SiO2-9.0Al2O3, molar basis) were evaluated. Dry powders of the raw materials (alumina and LZSA parent glass, frit) were uniaxially pressed (40 MPa) and the obtained compacts were sintered at 600-950 °C (1 h holding time). X-ray diffraction (XRD) study was performed in order to investigate the solid-state reactions occurred in LZSA-based compositions during sintering. XRD results were correlated to the CTE, E and εr of sintered samples. The CTE of the obtained composites decreased as alumina content increased mainly due to the β-spodumeness (solid solution Li2O.Al2O3.4-10SiO2) formation. The results concerning the E (22.3±1.5 GPa) and εr (3.1±1.3) for the composite with 5.6 vol% addition sintered at 850 °C for 1 h indicated, in a preliminary way, the possibility of development of materials with suitable properties for applications concerning to the low temperature co-fired ceramic (LTCC) technology.

XRD Study of the Influence of Heat Treatment on the Microstructure of Sol-Gel Processed ZrO2-Y2O3 Ceramics

1995 ◽  
Vol 398 ◽  
Author(s):  
C. Barrera-Solano ◽  
M. PiÑero ◽  
C. Jiménez-Solís ◽  
L. Gago-Duport
Keyword(s):  
Heat Treatment ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
Profile Function ◽  
Xrd Study ◽  
Different Temperatures ◽  
Hydrolysis Of Metal Alkoxides ◽  
Induced Changes ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis

ABSTRACTYSZ samples containing 5 and 10 mol% of Y203 were prepared by controlled hydrolysis of metal alkoxides. The dried powders were calcined at 800°C and then they were uniaxially pressed and sintered at different temperatures and next heated at 1400°C (∼ 5 MPa) or annealed at 1600°C for 24 h. The quantitative analysis of the experimental X-ray diffraction (XRD) spectra was performed by Whole Pattern Fitting (WPF). A Pseudo-Voigt (Thompson-Cox-Hastings) was used as shape profile function. The respective phase fractions (wt %) were fitted for both solid state solutions using the scale factor. The heat treatment induced changes are discussed.

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